Social Inequality
Long-Term Trends and Their Relationships with Happiness, Homicide Rates and Life Expectancy
Dr.Sabine Hoffmann, Mona Niethammer, Lona Koers, Marie Scherzer
2025-12-18
Agenda
Overview and Terminology
Research Questions
- How has social inequality evolved over time?
- How much do countries differ when it comes to social inequality?
- What is the relationship between social inequality and other factors?
Summary and Limitations
Overview
Data Preparing
Data Cleaning
- Do not interpolate missing data
- Use available data points
- Show real data
- Do not interpolate missing data
Data Filtering
- Time
Inequality over time (2000-2023)
Differences across countries(2022)
Inequality and its associated factors(2021) - Country
- Time
Weighting
Terminology
Gini Coefficient1
- Most widely used measure of income inequality
- Range: 0 = perfect equality, 1 = extreme inequality
- Most widely used measure of income inequality
Before-tax Income1
- Income received before taxes or government transfers
- Reflects market-based income distribution
- Income received before taxes or government transfers
After-tax Income1
- Income after subtracting taxes and adding government transfers
- Indicates resources actually available to households
- Income after subtracting taxes and adding government transfers
Source:[1] World Bank Poverty and Inequality Platform
Agenda
1. Overview and Terminology
Research Questions
How has social inequality evolved over time?
How much do countries differ when it comes to social inequality?
What is the relationship between social inequality and other factors?
3. Summary and Limitations
Global Trends
Agenda
1. Overview and Terminology
Research Questions
How has social inequality evolved over time?
How much do countries differ when it comes to social inequality?
What is the relationship between social inequality and other factors?
3. Summary and Limitations
Countries Difference
Agenda
1. Overview and Terminology
Research Questions
How has social inequality evolved over time?
How much do countries differ when it comes to social inequality?
What is the relationship between social inequality and other factors?
3. Summary and Limitations
Indicators
| Indicator | Concept | Unit |
|---|---|---|
| Happiness | Self-reported life satisfaction | 0-10 scale |
Happiness
Indicators
| Indicator | Concept | Unit |
|---|---|---|
| Happiness | Self-reported life satisfaction | 0-10 scale |
| Homicide rate1 | Number of deaths from homicide per 100,000 people | rate per 100,000 |
Source:[1] WHO Mortality Database
Homicide Rate
Indicators
| Indicator | Concept | Unit |
|---|---|---|
| Happiness | Self-reported life satisfaction | 0-10 scale |
| Homicide rate | Number of deaths from homicide per 100,000 people | rate per 100,000 |
| Life expectancy | average years that newborn is expected to live | year |
Life Expectancy
Agenda
1. Overview and Terminology
2. Research Questions
How has social inequality evolved over time?
How much do countries differ when it comes to social inequality?
What is the relationship between social inequality and other factors?
- Summary and Limitations
Summary
Social Inequality
- Global trend
- Downward trend
- Consistently high level
- Cross-country difference
- Large difference across countries
- Higher Gini linked to:
- Lower happiness
- Higher homicide rate
- Lower life expectancy
Limitations
Data Quality
- Data gaps
- Subjective indicators bias
- Data gaps
Research Design
- Single measure inequality indicator
- Cross-sectional data
- Single measure inequality indicator
Reference
- Joe Hasell (2023) - "Measuring inequality: what is the Gini coefficient?" Published online at OurWorldinData.org. Retrieved from: 'https://archive.ourworldindata.org/20251209-133038/what-is-the-gini-coefficient.html' [Online Resource] (archived on December 9, 2025).
- Joe Hasell, Bertha Rohenkohl, Pablo Arriagada, Esteban Ortiz-Ospina, and Max Roser (2023) - "Economic Inequality" Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/economic-inequality' [Online Resource]
- Bastian Herre, Fiona Spooner, and Max Roser (2013) - "Homicides" Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/homicides' [Online Resource]
- Bastian Herre and Fiona Spooner (2023) - "Homicide data: how sources differ and when to use which one" Published online at OurWorldinData.org. Retrieved from: 'https://archive.ourworldindata.org/20251125-173858/homicide-data-how-sources-differ-and-when-to-use-which-one.html' [Online Resource] (archived on November 25, 2025)
- Esteban Ortiz-Ospina and Max Roser (2017) - "Happiness and Life Satisfaction" Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/happiness-and-life-satisfaction' [Online Resource]
- Saloni Dattani, Lucas Rodes-Guirao, Hannah Ritchie, Esteban Ortiz-Ospina, and Max Roser (2023) - "Life Expectancy" Published online at OurWorldinData.org. Retrieved from: 'https://ourworldindata.org/life-expectancy' [Online Resource]